Field
The present invention relates to an optical scanning system and scanning lenses which are used for printers and the like.
Description of the Related Art
For the purpose of downsizing of printer devices, a shorter distance between a lens in the optical scanning system and the photoconductive drum or the scanning surface, that is, a shorter back focus is required.
Conventionally, optical scanning systems with a shorter back focus for tandem type color printers have been proposed (JP2004-361941A and JP2004-070190A, for example).
However, in an arrangement in which a lens is simply located in the vicinity of the photo conductor, efficiency of the optical system becomes lower, and therefore an amount of light becomes insufficient. Until now, an optical scanning system that has a shorter back focus and a higher energy efficiency and scanning lenses for realizing such an optical scanning system have not been developed.
JP2004-361941A
JP2004-070190A
Accordingly, there is a need for an optical scanning system that has a shorter back focus and a higher energy efficiency. The object of the present invention is to provide an optical scanning system that has a shorter back focus and a higher energy efficiency and scanning lenses for realizing such an optical scanning system.